Compact series-parallel, two stage centrifugal pumps



March 28, 1961 EVANS ET AL 2,976,810

COMPACT SERIES-PARALLEL, TWO STAGE CENTRIFUGAL PUMPS Filed Oct. 29, 1958 3 Sheets-Sheet 1 II-JVENTOR [041/3 5. [Vans fifchar'o C [W/n;

ORNEY L. B. EVANS ET AL March 28, 1961 COMPACT SERIES-PARALLEL, TWO STAGE CENTRI FUGAL PUMPS 3 Sheets-Sheet 2 Filed 001;. 29, 1958 March 28, 1961 B. EVANS ETAL COMPACT SERIES-PARALLEL, TWO STAGE CENTRIFUGAL PUMPS Filed Oct. 29, 1958 3 Sheets-Sheet 3 INVENTOR 100/5 5 [Va/76 fiat/70rd C. [W/ny BY Bun/n9 ATTORNEY COMPACT SERIES-PARALLEL, TWO STAGE CENTRIFUGAL PUMPS Louis B. Evans, Hastings, and Richard C. Ewing, St. Paul, Minn., assignors to Waterous Company, St. Paul, Minn., a corporation of Minnesota Filed Oct. 29, 1958, Ser. No. 770,335 7 7 Claims. or. 103-106) This invention relates to an improvement in compact series-parallel two stage centrifugal pumps and deals particularly with a pump of the type described which is relatively light in weight and unusually compact in design.

Most centrifugal pumps of the series-parallel type are large and bulky and require considerable space. it is a primary object of the present invention to provide a pump of this class which is so designed as to be extremely compact in form with a resultant very material decrease in weight from older designs.

A feature of the present invention resides in the provision of a two stage series-parallel pump having a novel type of easing design which results in a more compact form of pump than most pumps of this type. The pump housing is cored to provide passages closely connecting the first and second stages which results in the compactness and light weight previously mentioned.

These and other objects and novel features of the present invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of the specification:

Figure l is a top plan view of a two stage series-parallel pump, showing the general arrangement of parts therein.

Figure 2 is a side elevational view of the pump shown in Figure 1.

Figure 3 is a sectional view on a generally vertical plane through the impeller axis.

Figure 4 is a side view of the lower portion of the casing, a portion of the casing being broken away to disclose the transfer valve.

Figure 5 is a sectional view through a portion of the apparatus, the position of the section being indicated by the line 55 of Figure 3.

Figure 6 is a top plan view of the bottom portion of the pump housing to show the arrangement of ports in the main pump casting.

Figure 7 is a cross sectional view on the line 7-7 of Figure 6.

Figure 8 is a sectional view substantially on the line 3-8 of Figure 4.

The pump is indicated in general by the letter A and includes a main housing casting which is illustrated by the numeral 19. The housing 10 includes a first stage impeller chamber or volute 11 and a second stage impeller chamber or volute 12. The impeller chambers 11 and 12 are spaced apart to provide room for a first stage intake chamber 13 and a second stage intake chamber 14. These chambers 13 and 14 are spaced apart by a central partition wall 15 which is apertured as indicated at 16 to accommodate a removable hub portion 17. A bushing 19 is supported by the hub portion 17 and encircles the impeller shaft'20 which is supported to extend through the intake chambers and to support the first and second stage impellers 21"and 22 respectively in a manher which will be described.

The ends of the housing 10, on opposite sides of the impeller chambers 11 and 12, are provided with apertures 23 and 24 extending therethrough coaxial with the shaft niteci tates Patent the housing as indicated at 27 and 29 respectively, the closure plates being apertured as indicated at 30 and 31 to accommodate the impeller shaft 20-. Packing rings 32 and 33 are provided in cavities in the cover plates 25 and 26 encircling the shaft 2% and these packing rings are held in position by packing glands 34 and 35 which may be drawn toward the closure plates 25 and 26 by suitable bolts 37 and 39.

The closure plates 25 and 26 support concentric cylindrical flanges 40 and 41 which terminate in inwardly turned ring shaped flanges 42 and 43. A bearing 44 is supported within a bearing cap 45 attached to the flange 42, the bearing 44 supporting one end of the impeller shaft 20. A bearing 46 is supported inwardly of the flange 43 to encircle the impeller shaft 20 near the. opposite end thereof.

A gear casing indicated in general by the numeral 47 is secured to the flange 47 by bolts 49 or other suitable means. One side 50 of the casing 47 is bolted into surface contact with the flange 4'3 encircling the bearing 46 and this casing side 50 is also provided with an aperture 51 which supports a bearing 52. encircling one end of a which supports the outer race of a bearing 62 encircling the drive shaft 53, i The drive shaft '53 is provided with an extended end 63 projecting through the cover plate 56.

A gear 58 on the drive shaft 53 meshes with a gear 68 on the shaft 2% within the casing 47. Thus, rotation of the drive shaft 63 drives the impeller shaft 26' and the impellers 21 and 22 mounted thereupon.

Figure 6 of the drawings indicates the intake and outlet ports from the pump housing 10 and discloses a pair of side by side intake ports 64 and '65 and a pair of outlet ports 66 and 67. As is indicated in Figures 1 and 4 of the drawings, a transfer valve 69 is supportedin a chamber 70 at the upper end of the discharge passage 66-. The valve 69 is actually enclosed in a housing'or liner 71 which is inserted into the housing aperture 70, the liner 71 being apertured to fit the two outlets as will be described.

As is indicated in dotted outline in Figure 6 of the drawings, one passage 72 leads from the valve chamber 70 to communicate with the intake port or passage 65.

A second passage 73 leads from the valve chamber 70 to the discharge passage 67 from the second stage impeller. The valve 69 is so arranged as to selectively close either of these passages and open the other. In other words, the discharge from the first stage volute 11 may be directed through the passage 66, the valve 69, the valve housing 71 and the passage 72 to the intake passage leading from the port 65 to the intake of the second stage impeller 22, or may close the passage 72 and open the passage 73 to direct the discharge from the first stage volute to the discharge of the second stage volute 12.

Figure 7 of the drawings shows in partial section the two passages 72 and 73 which lead from the valve chamis a sectional view through the second stage impeller chamber, the impeller having been removed, showing the communication between the volute 12 and the passage A suction manifold 74 is mounted upon the upper sur- 7 3 face of the housing it) in communication with the ports 64 and 65. This suction manifold 74- is provided with an attaching flange 75 which is secured to the housing 10 by bolts 76 or other suitable means. The manifold 74 is provided with an opening at each end indicated by the numeral 77.

A discharge manifold 79 is also mounted upon the upper surface of the housing 10., The manifold 79 comprises a T-shaped body having open ends 80 and having at its lower end an anchoring flange 81 which is bolted or otherwise secured to the upper surface of the housing 10 as indicated at 8 2 As is best illustrated in Figure 2 of the drawings, the intake manifold 74 curves upwardly in one direction while the discharge manifold 79 curves upwardly in the opposite direction so that intake and discharge connections can be readily secured to either end of each of these manifolds.

As is indicated in Figure of the drawings, a flapvalve 83 is hingedly connected at 84 to the housing 10, the flap valve being positioned to close the connection between the intake manifold 74 and the intake chamber 14 when the intake chamber 14 of the second stage impeller 22 is subject to discharge pressure from the first stage impeller 21. As will be noted, the passage 85 leading from the intake manifold 74 to the intake chamber 14 is of slightly less dimensions than the portion of the intake passage within the body of the housing 10. When the valve 69 is in position to direct the discharge from the first stage impeller 21 through the passage 73 to the discharge manifold 79, the flap valve 83 will drop into the position shown in full lines in Figure 5 of the drawings by gravity. However, when the valve 69 is turned so that the discharge from the first stage impeller 21 passes through the volute 21, the discharge passage 66, the transfer valve 69 and into thepassage 72,'the force of fluid in the passage 72 swings the valve 83 into the position illustrated in dotted outline, closing communication with the intake manifold and permitting the discharge from the first stage to enter the intake manifold 14 of the second stage.

As is indicated in Figure 4, the valve 69 is provided with a valve stem 86 which projects upwardly above the top of the valve housing 71 and supports a gear segment 87. The gear segment 87 engages a cooperable gear segment 89 mounted upon an operating handle 90 which is pivotally supported at 91 to the housing 10. Pivotal movement of the handle 90 in one direction swings the valve 69 into position for series operation of the pump, and operation'of the handle 91 in the opposite direction swings the valve into position for parallel operation of the pump.

In accordance with the patent statues, we have described the principles of construction and operation of our improvement in compact series-parallel two stage centrifugal pumps, and while we have endeavored to set forth the best embodiment thereof, we desire to have it understood that changes may be made within the scope of the following claims without departing from the spirit of our invention.

We claim:

1. A centrifugal pump including a pump housing, said housing including a body including a pair of axially spaced impeller chambers and an intermediate partition, said body having intake chambers on opposite sides of said partition inwardly of said impeller chambers, said body having a pair of volutes communicating with said impeller chambers, said body also including a transfer valve chamber in communication with one said volute, and said body having passages extending from said transfer valve chamber to the other said volute and from said transfer valve chamber to the intake chamber of the impeller chamber of said other volute, a shaft. extending through said impeller chambers and said partition, means on said body for supporting said shaft, impellers on said shaft in said impeller chambers, a transfer valve in said' transfer valve chamber selectively connecting either of said passages to said one volute, a flat upper surface forming the top of said body, said surface having a discharge port therethrough communicating with said other volute, a discharge manifold connected to said surface in communication with said discharge port, said surface having ports therethrough communicating with said intake chambers, and a common intake manifold secured to said surface in communication with said last named ports.

2. A centrifugal pump including a pump housing includinga pair of axially spaced first and second stage impeller chambers, said housing including suction chambers between said impeller chambers and connected thereto, and said housing including a partition between said suction chambers, an impeller shaft supported by said housing and extending through said impeller chambers and said partition, impellers on said shaft within said impeller chambers, said housing having a substantially fiat upper surface, said housing having first and second stage suction passages extending upwardly from said suction chambers to said upper housing surface, said housing having a discharge passage extending from said second stage impeller chamber to said upper housing surface, said housing have a transfer valve cavity in said upper housing surface and having a discharge passage extending upwardly from said first stage impeller chamber and said transfer valve cavity said housing having transverse passages from said valve cavity to the second stage suction passage and from said valve cavity to said second stage dissaid upper housing surface and connected to said suction passages, and a discharge manifold secured overlying said upper housing surface and connected to said second stage discharge passage.

3. The structure of claim 2 and including a valve in said second stage suction passage for selectively closing said last named passage from communication with said intake manifold. I,

4. The structure of claim 2 and in which the first stage discharge passage extends axially into said valve cavity, and in which said transfer valve includes a hollow cylindrical body through which fluid may flow.

5. A centrifugal pump including a pump housing including a pair of axially spaced first and second stage impeller chambers, said housing includingsuction chamers between said impeller chambers and connected thereto, and said housing including a partition between said suction chambers, an impeller shaft supported by said housing and extending through said impeller chambers and said partition, impellers on said shaft within said impeller chambers, said housing having a substantially flat upper surface, said housing having first and second stage suction passages extending upwardly from said suctions chambers to said upper housing surface, said housing having a discharge passage extending from said secong stage impeller chamber to said upper housing surface, said housing having a transfer'valve cavity in said upper housingsurface and having a discharge passage extending upwardly from said first stage impeller charm her and said transfer valve cavity, said housing having transverse passages from said valve cavity to the second stage suction passage and from said valve cavity to said second stage discharge passage, a tranfer valve in said valve cavity for selectively connecting said first stage discharge passage to said second stage suction passage on said second stage discharge passage, said transfer valve including a hollow cylindrical body rotatably supported in said valve cavity, the first stage discharge passage extending axially into said valve cavity and communicating with the interior of said valve body, and said valve body including an opening through its cylindrical wall selectively registrable with said transverse passages, an intake manifold secured overlying said upper housing surface and connected to said suction passages, and a discharge manifold secured overlying said upper housing surface and connected to said second stage discharge passage.

6. The structure of claim 5 and including valve means in said second stage suction passage for selectively closing said last named passage from communication with said intake manifold.

7. The structure of claim 6 and in which said last named valve means is automatically operated to close communication With said intake manifold when said pas- References Cited in the file of this patent UNITED STATES PATENTS 2,274,763 Yates Mar. 3, 1942 FOREIGN PATENTS 295,133 Germany Nov. 10, 1916 

